[ltp] Brightness problem on x301 running Debian Lenny

[Per Dalgas Jakobsen]

Hi,

I have a strange problem on my x301 with the monitor brightness. It is 
like the actual brightness level lacks one behind all the time, let me 
explain:
---
I press Fn+Home (brightness up) until the monitor is as bright as 
possible, then pressing Fn+End (brightness down), does nothing, second 
Fn+End brings down the brightness, if I then press Fn+Home, the 
brightness goes down once more (not up), the next brightness adjustment 
will go up no matter which Fn+Home or Fn+End I press, because I pressed 
Fn+Home previously.

I also tried to write values directly to the 
/proc/acpi/video/VID/LCD0/brightness:
---
# echo 100 >/proc/acpi/video/VID/LCD0/brightness (behaviour depends on 
previous adjustment)
# echo 80 >/proc/acpi/video/VID/LCD0/brightness (brightness goes to 100)
# echo 70 >/proc/acpi/video/VID/LCD0/brightness (brightness goes to 80)
# echo [any number] >/proc/acpi/video/VID/LCD0/brightness (brightness 
goes to 70)

I'm running a self-compiled (and self-configured) kernel version 2.6.28 
- Almost all used modules are compiled into the kernel.
I've tried to run an Ubuntu LiveCD - That one operates as expected.

Any ideas of why Debian Lenny with kernel 2.6.28 does not behave 
reasonable on LCD brightness changes?

~Per